brake booster leak?

['72f250]

my truck is a '72 f250 with power brakes. when the truck is running and you press the pedal, there is a loud whooshing noise coming from under the dash. the brakes work fine but the noise is really annoying. if you press the pedal as far as itll go, the noise quits but its hard to keep the pedal pressed that hard at a traffic light. any ideas?

[FORDification]

Internal booster leak...probably a ruptured diaphram. It's not repairable. Looks like you'll be looking for a replacement soon.

[heep70]

Isn't that noise normal because it is sucking air into the back of the booster when pushing the pedal?

Or is it making that noise all the time? Then it would be a busted booster.

[FORDification]

No, the booster can't be sucking air at any time...that would constitute a vacuum leak. The only 'open' area of a booster is the vacuum hose connection on the front. That sucking noise is definitely not normal.

['72f250]

well i figured that was it but i was hoping it wasnt. should i replace it now or is it safe to wait until it dies completely. im a little low on funds right now. ive been driving the truck since March and its made the noise since then. the brakes still feel fine.

[mjhaltom]

I drove my '85 F150 for a year like that. You would still have brakes if it failed, but broken power brakes are harder to push than maunaul brakes.

[Faithful Old Road Dog]

I had the same issue when I bought my truck. It still stopped, but the noise was obnoxious. It cost me about $100 for a rebuilt.

[kid]

My 350 had that sound. I adjusted the brake rod and it went away.